Problem with Solve a Differential Equation

Question

I Have a little problem . I wrote this function ( function describe dynamics of ball-hoop system):

soln = NDSolve[{7000*q''[t] + 20000*q[t] - 800*f''[t]*f[t] == 0, 
    896*f''[t] - 480*h''[t] + 7848*f[t] - 800*q''[t]*f[t] == 0,
    900*h''[t] - 480*f''[t] + 20000*h[t] == 0,
    q[0] == 0.1, h[0] == 0.1, f[0] == 0.},
   {q[t], f[t], h[t]},
   {t, 0, 5}];)

After i run it,program show mi this comunicate

NDSolve::deqn: "Equation or list of equations expected instead of False in the first argument "Here is my code", False, h[0] == 0.1`, False}\). "

Anybody now what is wrong ?

Answer 1

In this Mathematica code, please enter the following instead:

soln = NDSolve[{7000*q''[t] + 20000*q[t] - 800*f''[t]*f[t] == 0, 896*f''[t] - 480*h''[t] + 7848*f[t] - 800*q''[t]*f[t] == 0, 900*h''[t] - 480*f''[t] + 20000*h[t] == 0, q[0] == 0.1, h[0] == 0.1, f[0] == 0.}, {q[t], f[t], h[t]}, {t, 0, 5}]

Removing the last couple of characters should do ok to solve the problem.